Optoelectronic apparatuses, such as an optical proximity sensor type apparatus, may include a light source and an adjacent photosensitive light detector. Such an optical proximity sensor can be used to detect the presence of an object, estimate proximity of an object and/or detect motion of an object, based on the magnitude and/or phase of light originating from the light source that is reflected from an object and detected by the light detector. The value of these sensors has become more important with the advent of battery-operated handheld devices, such as mobile phones. For example, a fair amount of the energy from a mobile phone battery is used to drive the display, and there is value in turning off the display or backlight when the mobile phone or other device is brought to the user's ear (where it cannot be viewed anyway). Optical proximity sensors, which are examples of optoelectronic apparatuses, have been used for this, and many other applications.
For other examples, there are many other applications in which the presence of an object can be detected with an optical proximity sensor to advantage. These range from sensing when protective covers have been opened on machinery, paper has been positioned correctly in a printer, or an operator's hands are at risk near an operating machine. An optical proximity sensor can also be used as a simple touch or near-touch activated switch, and could be implemented in applications like keyboards or devices that have a plastic housing that is sealed but which allows the light from the source to pass through and be sensed by the detector on the return.
Since more and more optoelectronic apparatuses are being integrated into products, such as mobile phones, there is a desire to provide smaller and cheaper optoelectronic apparatuses. Preferably, manufacturing of optical proximity sensors, as well as other optoelectronic apparatuses, should be relatively simple and should provide a high yield.